Slave I and the Asteroid Hit

In Attack of the Clones, we see a pursuit of Slave I by Obi-Wan
in a 'Jedi Fighter' backfire, leading to Slave I chasing Obi-Wan through
an "asteroid field", which is the ring of planet Geonosis. In the midst
of this chase, we see a shot from Slave I destroy half of an asteroid.
The size of the asteroid is 8 meters, as judged from the ~4 meter wide fighter. This means
that Slave I fragmented a mere 3-4 cubic meters of asteroid, without
significant vaporization or melting. Calculations will soon follow.

Using Wong's own asteroid calculator
(since I explicitly haven't worked that scene yet), and inputting the high-side
estimate of 10 meters for the asteroid, one finds that the required cratering energy (i.e. the energy
required to make a crater equal to the radius, which is pretty much the effect
seen) would be only .2 tons (0.84 gigajoules, or 840 megajoules) for solid
granite. Even if we
assume that these are magic planetary rings made of nickel-iron (as opposed to
common rings made of far lesser materials, usually ice or sometimes collections
of dust and dirt clods), we're only up to 19.7 gigajoules for the overestimate
asteroid, from a vehicle significantly larger than a fighter.